Your post wasn't clear on what this resume is for. If you're asking for your AMCAS application, then you should absolutely follow the advice above. If this is a resume for a job or volunteer position, it's a different story. I would only include this information if you're lacking in much practical experience.
Personally, when I look at resumes, I could care less about shadowing. (I'm in charge of interns and volunteers at a non-profit) Following a doctor around for 15 hours doesn't say anything about your relevant skills or work ethic that would make me confident that you are the one for the job. Only med schools care about shadowing because it shows that you have an interest in learning more about the medical profession.